Global CO2 storage capability could also be drastically overstated, examine finds

A brand new evaluation means that the “prudent” storage accessible for carbon dioxide to move off additional international warming is extra restricted than different latest estimates.

Accounting for the dangers related to carbon seize and storage (CCS), the study discovered that stashing carbon underground in appropriate areas would probably scale back warming by solely about 0.7° Celsius (1.3° Fahrenheit). That determine is much beneath different estimated potential reductions of 5-6°C (September 11°F), doubtlessly making CCS much less promising than believed.

The most typical type of CCS entails injecting CO2 into underground rock formations, which in principle would lock it away and out of the ambiance for millennia. Past research suggests there’s house on Earth to retailer 8,000-55,000 gigatons of CO2, main some to conclude that the potential for CCS is nearly boundless. However, more moderen research have proven the constraints of this system.

This newest analysis, revealed Sept. 3 within the journal Nature, finds that most of the potential areas for CCS on Earth could also be too dangerous to make use of. The paper argues that CCS must be used judiciously to cope with CO2 emissions, reserving it for carbon-intensive power functions that aren’t simple to switch with renewable options, corresponding to agriculture, mentioned Matthew Gidden, the examine’s lead creator and a senior researcher within the International Institute for Applied Systems Analysis in Austria. Meanwhile, society might save that treasured carbon space for storing by greening international transportation.

“We know that geologically storing carbon is likely to be a very important tool in the toolbox in order to achieve net-zero and net-negative CO2 emissions,” mentioned Gidden, additionally an affiliate analysis scholar on the University of Maryland within the U.S. But efficient use of CCS, given its availability, requires treating it as a restricted useful resource, in line with the researchers.

“There are trade-offs, not only today in terms of what we’re planning to do, but also in the future,” he informed Mongabay. “So what options are we leaving future generations?”

Gidden and his co-authors notice that CCS is a essential a part of nations’ local weather commitments, in step with the purpose of the Paris Agreement to limit common international warming to 2°C (3.6°F) above pre-industrial ranges. However, CCS has been gradual to ramp up, with extensively differing hypotheses about how a lot carbon we are able to really retailer.

So the workforce got down to discover out the “prudent” limits on CCS. They mapped out areas for geologic storage globally, discovering room for a complete of 11,800 gigatons of CO2. They then excluded sure areas due to the chance of contaminating water sources, setting off earthquakes, or CO2 leakage. They additionally omitted websites inside 25 kilometers (16 miles) of populated areas. They concluded that these dangers drastically decreased the quantity of accessible storage to round 1,460 Gt of CO2.

“[T]he research correctly frames geological storage as a finite intergenerational resource requiring strategic management,” Jarad Daniels, CEO of Australia-based nonprofit Global CCS Institute (GCCSI), wrote in an electronic mail to Mongabay. “This supports prioritising CCS for essential applications — industrial point sources that cannot be electrified and durable carbon removal technologies.”

Daniels additionally mentioned the analysis “confirms that geological storage remains more than sufficient for CCS to play a crucial role in limiting global warming.” Still, he mentioned he believes their strategies rested on “overly restrictive assumptions about risk and technical parameters of CCS projects.” For one factor, Daniels mentioned, a 25-km buffer for human settlements is “conservative,” and he pointed to examples of CCS presently in progress, corresponding to Carbfix in Iceland, that sit nearer to inhabitants facilities. Elsewhere, others, like the Northern Lights project in Norway, inject CO2 to depths higher than these utilized by Gidden and his colleagues.

“Existing projects demonstrate through rigorous permitting and risk assessments that high safety standards can be met in practice,” Daniels added.

Gidden mentioned the uncertainty round viable and secure CCS makes it essential to supply real looking numbers that policymakers can use in plans to deal with local weather change, particularly over time. Scientists nonetheless aren’t certain that eradicating CO2 from the ambiance will decrease the worldwide temperature by the identical quantity that it rises when CO2 is emitted, for instance.

To Daniels and the GCCSI, the findings level to the necessity for enhancing CCS functionality as rapidly as doable.

“Immediate action is imperative,” he mentioned. “This study reinforces that every year of delay makes climate goals more difficult and expensive to achieve.”

CCS is essential for mitigating local weather change, Gidden mentioned. But, he added, present projections point out that the worldwide temperature might rise to three°C (5.4°F) above the pre-industrial common by 2100. That means the potential for CCS that he and his colleagues mapped out wouldn’t be sufficient to carry temperatures again throughout the Paris Agreement’s 2°C threshold.

Instead, halting and reversing local weather change would require lowering carbon emissions as quickly as doable and investing in different options, the authors write. Gidden identified that forests and different terrestrial ecosystems presently draw 2 Gt of CO2 from the ambiance — greater than another technique.

“That is a number that we can sustainably expand,” he mentioned. “We can do more reforestation, we can do more conservation. We can take care of and conserve our natural biomes.”

And that technique comes with “co-benefits,” he added, such because the safety of different ecosystem companies and biodiversity.

“We really need to be using all available tools in our toolbox,” Gidden mentioned, “and that leads with conservation of natural carbon sinks.”

Banner picture: In August 2025, CO2 was saved for the primary time in Norway-based Equinor’s Northern Lights reservoir outdoors the town of Bergen. Image courtesy of Torstein Lund Eik/©Equinor.

John Cannon is a workers options author with Mongabay. Find him on Bluesky and LinkedIn.

Citations:

Gidden, M. J., Joshi, S., Armitage, J. J., Christ, A.-B., Boettcher, M., Brutschin, E., … Schleussner, C.-F. (2025). A prudent planetary restrict for geologic carbon storage. Nature, 645(8079), 124-132. doi:10.1038/s41586-025-09423-y

Kearns, J., Teletzke, G., Palmer, J., Thomann, H., Kheshgi, H., Chen, Y.-H. H., … Herzog, H. (2017). Developing a constant database for regional geologic CO2 storage capability worldwide. Energy Procedia, 114, 4697-4709. doi:10.1016/j.egypro.2017.03.1603

Zhang, Y., Jackson, C., & Krevor, S. (2024). The feasibility of reaching gigatonne scale CO2 storage by mid-century. Nature Communications, 15(1), 6913. doi:10.1038/s41467-024-51226-8

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